[Bug debug/47780] New: -fcompare-debug failure with -O -fgcse -fgcse-las -fstack-protector-all

["zsojka at seznam dot cz" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47780

           Summary: -fcompare-debug failure with -O -fgcse -fgcse-las
                    -fstack-protector-all
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zsojka@seznam.cz
                CC: aoliva@gcc.gnu.org
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu


Created attachment 23377
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23377
reduced testcase

Compiler output:
$ gcc -O -fgcse -fgcse-las -fstack-protector-all -fno-tree-ccp
-fno-tree-dominator-opts -fcompare-debug testcase.c                     
testcase.c: In function 'foo':
testcase.c:3:6: note: The ABI for passing parameters with 128-byte alignment
has changed in GCC 4.6
gcc: error: testcase.c: -fcompare-debug failure (length)

Generated code is different with/without -g.

Tested revisions:
r170243 - fail
4.5 r170013 - fail